In the prior art of long standing, microscopic examinations and analyses have been performed traditionally in the biomedical, metallurgical and other research areas. Of more recent vintage, these microscopic analyses have been automated by means of some type of computerized system.
For example, a semi-automatic computer-microscope has been employed for the analysis of neuronal morphology, namely, for computing and drawing chordal approximations of a basal dendrite system. The computation is performed by means of conventional electronic analog techniques, and the chordal distances are computed according to the Pythagorean theorem by means of squaring, summing and square rooting. The inputs to the computer section of the instrument are linear-motion transducers fixed to the stage of the microscope along the three coordinate axes. There are two output devices: one, a digital printer, which prints on paper tape the distance measurements in micra; and two, a plotting board on which is drawn a two-dimensional projection of the neuron.
In another example, intended for chromosome analysis, a high-magnification microscope has been fitted with a camera lucida (or optical beam splitter) juxtaposed to, and aligned with, a graphics tablet. This arrangement superimposes an image of the graphics tablet upon the image of the preparation. The operator then uses a hand-held stylus to trace and enter selected pictorial data into the memory of a computer.
These semi-automated systems are intended primarily for computation, tracing and data recordation; and while some degree of operator control is provided, the microscope's imaging system provides no information feedback from the computer to the operator. Thus, the operator has no readily available means to compare and selectively investigate the present data (or preparation) in its visual relationship to the data stored in the computer's memory, nor to readily control the microscope via the computer.
As a further development in the prior art, highly automated computerized systems have been developed for very specific biomedical purposes in clinical applications. For example, a scanning automated microscope system has been disclosed for performing leukocyte counts and red blood cell morphology studies. This microscope system has an automatic stage control device, operating along X, Y and Z axes, plus an automated cell-finding processor. The cells are located automatically along a conventional meander search pattern, are centered in the field of view, and are focused automatically. The cells can then be observed either through a color television monitor or through the oculars of the microscope. This system is essentially a clinical laboratory instrument intended to be used by technicians or semi-professionals working in conjunction with pathologists. Operator input is facilitated by means of a keyboard--requiring the operator to look away from the microscope--and there is no electronically-produced image from a graphics display which is optically superimposed upon the visual image of the preparation in the microscope.
Another example is a "flying spot" scanner system intended for automated dendrite tracking. The major components of this system are a microscope, a digital computer, and an image dissector. The image dissector converts the optical density information of the microscope into analog electrical signals suitable for input to the analog-to-digital converter of the computer. There are two optical paths from the respective eyepieces of the microscope, one to the image dissector, and the other to an oscilloscope via a lens and mirror arrangement. The computer drives respective stepping motors to move the microscope along X, Y and Z axes. A joy stick and "button box" facilitate operator interaction with the computer, as the operator views a back-projected image of the microscope field on a projection oscilloscope. In order to select a cell whose dendrites are to be measured, the operator uses the joy stick to move the microscope stage via the computer and stepping motors; and at the same time, the operator may alter focus by means of the button box, which via the computer, actuates a fine-focus stepping motor subsystem. While that degree of operator interaction is provided, nevertheless, this automated system lacks the facility for total operator intervention, while looking into the microscope and viewing the preparation under optimum optical conditions. With the prior art system, the operator must look at a back-projected image of the preparation, and hence there is a loss of resolution resulting in an image of reduced quality. In addition, the back-projected image requires very high levels of illumination intensity, which tend to bleach certain preparations (particularly some fluorescent dyes). This bleaching action is very detrimental in microscope examinations. Moreover, the described prior art system does not provide an on-line graphic display of the data being acquired; it provides the graphics display of the preparation being examined only at the completion of the automatic data-acquisition phase of the program. Even then, only the pictorial component is made available to the operator on the graphics display.
These automated computerized microscope systems utilize the computer to assist in or to replace the tedious manual manipulations inherent in certain analyses performed with a microscope. The whole thrust of these rather sophisticated developments is to minimize the degree of operator intervention, reduce operator time and hence lower the operating costs, and yet improve the accuracy and reliability of measurement and data collection. As a result, these automated systems are primarily intended to be used by technicians for very specific well-defined purposes, and these systems are not well suited for use by research scientists in investigations requiring a high degree of interaction between the operator and the system. This high degree of interaction is desirable in order to preserve operating flexibility and to take advantage of human judgment in controlling data acquisition.